Desk and chair for schools



(No Model.) 2 Sheets-Sheet 1..

G. A, BOBRIGK. DESK AND OHAIR FOR SCHOOLS.

f No. 404,250. atented May 28, 1889; f3 -1- 2 Sheets-Sheet 2.

(No Model.)

G. A. BOBRIGK. DESK AND CHAIR FOR SGHOOLS.

atented May 28, 1889.

N PETERS. Fhnwnilfingm her. Washlngkon. D. C

UNITED STATES PATENT OFFICE.

GABRIEL A. BOBRICK, OF BOSTON, MASSACHUSETTS.

DESK AND CHAIR FOR SCHOOLS.

SPECIFICATION forming part of Letters Patent No. 404,250, dated May 28, 1889.

Application filed September 15, 1838. Serial No. 285,523. (No model.)

T0 at whom it may concern:

Be it known that I, GABRIEL A. BoBRIcK, a citizen of the United States, and a resident of Boston, in the count y of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Desks for Schools; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to m ake and use the same, reference being had to the accompanying drawings, which form a part of this specification, and in which I Figure 1 is a perspective View of a schooldesk embodying my improvement. Fig. 2 is a similar view, showing the detachable gearwheel removed after the desk-body shall have been adjusted by it to its proper elevation. Fig. 3 is a vertical crosssection through the desk and its fixed standard, showing the detachable gear-wheel in its operative position. Fig. 4 is a perspective view of the detachable gear-wheel removed from the standard. Fig. 5 is a detail view of the hub of said gear-wheel, and Fig. 6 is a perspective detail View of the upper part of the tubular fixed standard.

Like letters of reference denote corresponding parts in all the figures.

This invention has relation to that class of desks for schools in which the desk-body or chair-seat, as the case may be, is capable of vertical adjustment, so as to adapt it to scholars of different size and grade; and it consists in certain improvements upon the desk for which Letters Patent of the United States No. 37 0,923 were granted to me on the 4th day of October, 1887, which said improvements will be hereinafter more fully described and claimed,

Reference being had to the accompanying two sheets of drawings, on which I have shown this improvement as applied to a school-desk, the letter A designates the tubular standard which forms the fixed support for the adjustable desk-body shown at B. The latter is provided with a screw threaded shank, G, which projects down into the tubular standard and has a longitudinal groove or recess on one side, (denoted by the letter D.)

The threaded shank O is of such a diameter that it will work loosely up and down through the aperture or opening at the upper end of the fixed standard A,whieh is provided, near its upper end and on one side, with a bulge or proj cction, E, projecting inwardly toward that side of the desk where the scholar is seated. This bulge forms a shield or cover for the miter-wheel, F, which has a screwthreaded hub through which the threaded shank C is inserted. The miter-wheel F is further provided with a smooth upper and lower rim, (shown at G and H, respectively,) which form bearing-surfaces against flanges g 71 formed by cutting away a portion of the standard opposite to the bulge or cover E. In order to compensate for this cutting away of the standard, in order to provide an open ing through which the rim of the miter-wheel may project, the bulge or cover E is thickened or re- 3n forced by webs of metal, (shown at 6,) connecting the head or top of the standard with the lower part of the same in such a manner that the body of the standard shall not be materially weakened or suffer in strength to any injurious extent by providing the opening through which the rim of the miter-wheel projects.

That side of the standard which faces the longitudinal groove D in the threaded shank is provided with one or more intcriorlythreaded bearings, I, through which set-screws or binding-screws J are inserted, the inner ends of which project into the groove D, so as to prevent the threaded shank from turning during the process of raising or lowering it by revolving the miter-wheel F. These setscrews have an additional or supplementary functionvi7., to bind the shank in its adj usted position, which may be done, after the desk has been raised to the proper elevation, simply by turning them through their respective bearings until their inner ends shall bear against the bottom of groove D. In order that these screws may be readily manipulated, I provide them,preferably, with square heads j, which may readily be fitted and turned by means of a wrench or key.

The tubular standard is provided, in addition to the bearings which receive the setscrews, with an interiorly threaded bearing (shown at K) adapted to receive the inner threaded end, Z, of the hub L, the outer end with one or more series of openings or apertures (shown at I) for the twofold purposev of which is provided with a handwheel, M, by means of which it may readily be screwed into and again removed from its appropriate bearing. Upon this hub L is journaled a large gear-wheel, N, which meshes or miters with the miter wheel or pinion F, hereinbefore described. It follows that when the hub is screwed into its proper position on the standard, so as to cause the teeth or cogs of the gear-wheel N to engage those of the pinion or miter wheel F, by revolving the wheel N by means of its crank or handle 0 the miter-wheel F will also be rotated in its bearing within the tubular standard, thereby gradually raising 'or lowering the threaded shank which passes through it, and with it raisin g or lowering the desk-body, as the case may 1 be, according to the direction in'which wheel N It is obvious that before the in- T termeshing gears can be operated for the purstandard, and means, substantially as dois revolved.

pose of adjusting the elevation of the desk, as

aforesaid, the bindin -screws J must be loosened, so as to permit of the free motion up or down of the threaded shank.

The tubular standard through which the threaded shank works, and which forms the fixed support for the desk, may be provided of saving metal and reducing the weight of the standard, and these apertures also serve i as gages or indicators for regulating the ad j ustment of the movable shank. By bringing the lower end of the shank opposite to any one turning the binding-screws until they shall press or bear with their inner ends against the bottom of the groove in the shank. Vhen it is at any time again desired to change the elevation of the desk, then this may be done in a moment of time by simply loosening the binding-screws and adjusting the removable gear-wheel in its operative position.

l'lavin g thus described my invention, I claim and desire to secure by Letters Patent of the United States- 1. The combination of the tubular standard having an enlarged upper slotted portion, the threaded shank havingalongitudinal groove, binding-screws inserted through the side of the tubular standard and projectinginto the groove in the threaded shank, the miterwheel having upper and lower flat bearingsurfaces engaging, respectively, the upper and lower parts of the cut-away portion of the scribed, for operating said miter-wheel.

2. The combination of the tubular standard, constructed substantially as described, the longitudinally grooved shank supporting a desk or chair body, one or more bindingscrews inserted laterally through the standard and projecting into the groove in the threaded shank, the mitcr-wheel working upon said shank and projecting through an aperture in the tubular standard, and the removable gear-wheel detachably connected to the standard and adapted, when in its operative position, to engage and operate the initer-wheel, all. constructed and combined to operate substantially in the manner and for the purpose shown and set forth.

In testimony that I claim the foregoing as myown I have hereunto affixed my signature in presence of two witnesses.

GABRIEL A. l-EOBRIUK. lVituesses:

CHAS. HALL ADAMS, E Dwain) 1 3. SPIKE. 

